I am using the 6600M and have the "Monitor Tx signal on waterfall" checked under the radio setup. When I transmit the waterfall turns Black and only the Spectrum display shows the Tx signal. Is there another setting to get the Tx signal to show on the waterfall?
As an addendum to my question, it was found that I was only using 11w to drive my amp when I tried to see my transmit signal on the waterfall. It was pointed out by a few this evening in a QSO that theirs was working but their transmit power was in the >40W levels. I am running the German RF 2K+ Dual LDMOS Amp. I tried the transceiver alone at 45 w and the monitor on the waterfall worked. So, it appears I wasn't driving the transceiver hard enough for the monitor ckt to work as designed. Unfortunately, both the SSDR and 6K Transceiver manuals do not go into any detail describing this waterfall monitor set up. Maybe in a future update it will be corrected.